e34john

17's will generally be more comfortable as everyone said but also the type and rating of the tires play a big part. Really sporty tires with a stiff sidewall will not ride as good as something like an all season tire. All seasons will be quieter and ride better, they don't look as good though.

toantran99

Where can I purchase this "sport" rear bar?
Thanks.

When we purchased our LS 430, there were not any "Sport" packages available locally, but all the So. Cal. cars seemed to have 18s vs 17s. I'm not unhappy with the fairly soft springs on the standard suspension operating with the 18s, but I did install the "Sport" rear roll bar (roughly $120 for the bar and bushings) and that did cut down on some of the understeer.

A bit of research indicates that the "Sport" package consisted of the increased dia rear roll bar, stiffer springs and stiffer shocks. I think the stiffer springs were also sold in some markets as the "rough road" option.

Fussy

Cars always ride softer and quieter on higher side walls. I have just bought tires for our 2004 LS430, after much study I chose the Michelin Primacy 3 ST. Instead of the standard 245/45/18 I put on 235/50/18 and as expected the ride is definitely softer and quieter than the worn out Continental Conti max. The Michelin tires were not cheap at $280 AU each (212.81 American) but they improved the ride, noise levels and steering too although our car still has some camber issues...

I found an excellent site which shows the wheel / tire configuration and any differences in size, circumference, speed of revolution the lot and the speedometer reading change is minimal at about 1.5km less.

One thing I did learn is that all tires have a DOT code which tells you when they were made, when I ordered the tires I phoned Michelin Australia and asked if they had tires less than 3 months old cause for that price I didn't want some 2 year old tires which can often happen and you end up with tires that are going hard....they told me they had fresh tires so when I was at the tire shop I checked all four and they were all well less than 3 months old.

When I get some money I fully intend to improve the ride yet again by changing the 18 wheels to Rev 100 Classic 16 inch wheels on which I will have 235/60/16 Michelin Primacy 3 ST tires put on as this will give the best quality ride and there is virtually no change to speedometer as this configuration is almost the same as the original 18 inch wheels and tires .

There should be no issue as the year 2000 to 2003 ls430 cars had 16 inch wheels which changed to 17 inch in 2003 then 18 inch for 04,05,06.. we own a 1985 Jaguar series 3 Sovereign which is nearly as heavy as the LS430 and she has 205/70/15 wheels / tires and rides better for it.

As far as I'm concerned cars look and ride much better with decent size tire wall tires on them and those cars with 20 inch rims and licorice strap tires look stupid and would have a seriously crap ride quality, really low profile tires are for the race track not luxury motoring.